Flow control valve

ABSTRACT

A flow control valve employs a ported cup which slides within an opening in a stationary member under increasing pressure differential and against the action of a spring, so that pressure differential changes have little or no effect on the rate of flow through the valve. A cylindrical side wall of the cup is provided with a plurality of axially extending duplicate series of circumferentially staggered separate port segments, the port segments in each of the series decreasing in circumferential width toward a closed end of the cup. Adjacent port segments in the series have end boundaries in substantially the same transverse plane normal to the cup axis, and one side boundary of each port segment in the series lies in a plane containing the axis of the cup. The shape and pattern of the port segments provide greater cup strength and minimize trapping of foreign objects carried by the fluid.

O Umted States Patent 1 1 3,752,184

Griswold Aug. 14, 1973 FLOW CONTROL VALVE Primary Examiner-Henry T.Klinksiek 75 l t D ldE.GriswoldC DelM I 1 z Attorney-Charles 0. Lyon eta].

73 A G [22] Fsslgnee riswold Controls, Santa Ana Calif ABSTRACT 1 lled'1971 A flow control valve employs a ported cup which slides [21 Appl.No.: 204,027 within an opening in a stationary member under increasingpressure differential and against the action of 52 [1.8. CI. l 7 aspring so that pressure differential changes have E 51 1 Int. Cl 321;233:7 3 or no effect on the rate of flow through the valve. A cy- 58]Field 504 517 lindrical side wall of the cup is provided with aplurality 137/512 37 625 of axially extending duplicate series ofcircumferentially staggered separate port segments, the port seg- 56ments in each of the series decreasing in circumferen- 1 'ggTg; m tialwidth toward a closed end of the cup. Adjacent port S A NTS segments inthe series have end boundaries in substan- 3,131,716 5/1964 Griswold 51al 137/517 X the sane transverse plane nomal to the gup axis, 3,256,9056/1966 Gnswold et al 137/517 X and one side boundary of each portsegment in the 3353 ries lies in a plane containing the axis of the cup.The 3:285:282 5/1966 Martin "111:: i 37/s04 x shape and Patten f pmvidei 3,540,484 11 1970 Brown er al. 137/503 x cup stength and "aPPmg fmelg"b1ects rIrI carried by the fluid.

m5," 5 EEETIIZFigui-es Patented Aug. 14, 1973 2 Sheets-Sheet 2 FLOWCONTROL VALVE This invention relates to flow control valves of thegeneral type shown in U. S. Pat. Nos. 3,131,716 granted May 5, I964, and3,256,905 granted June 21, I966. The flow control valves shown in thosepatents each employs a ported cylindrical cup axially slidable through acircular opening in a stationary orifice plate. A pressure differentialacross the cup causes it to slide through the plate opening against theaction of a spring. Such movement changes the total combined area of aseries of continuous tapered ports exposed to upstream pressure, so thatthe flow rate remains substantially constant regardless of the pressuredifferential.

The long tapered symmetrical ports shown by these prior patents tend toweaken the structural strength of the movable cup so that the cupcylinder may require reforming after the ports are cut. If thecylindrical cups are to be precision finished as by a centerlessgrinder, the surface areas interrupted by the symmetrical continuousports cause difficulty in the grinding operation. Furthermore, foreignobjects carried by the fluid are apt to be trapped or wedged alongtapered portions of the symmetrical ports.

It is the principal object of the present invention to avoid the abovenamed difficulties by providing one or more series of circumferentiallystaggered separate port segments which regulate fluid flow in the samemanner as the long continuous symmetrical segments shown in said priorpatents. The staggered port segments provide interlaced metal sectionswhich contain more of the cylindrical structure, provide greaterstrength and eliminate the need for reforming the cylindrical portionafter the ports are cut. When the cylindrical cups are precisionfinished, the port segments produce an interlaced metal pattern thatprovides a more continuous circumferential surface condition, andconsequently ground surfaces are more uniformly cylindrical. Moreover,the port segments tend to pass or cut off foreign matter rather than tocause it to be wedged or trapped within the tapering boundaries of theport.

Other and more detailed objects and advantages will appear hereinafter.

In the drawings:

FIG. 1 is a longitudinal sectional elevation showing a preferredembodiment of this invention.

FIG. 2 is a sectional elevation showing a plurality of the FIG. 1devices mounted in a common housing.

FIG. 3 is a side elevation partly broken away, showing a portion of thedevice of FIG. 1 on an enlarged scale.

FIG. 4 is a diagrammatic developed view of the cylindrical portion ofthe cup shown in FIG. 3 and illustrating six separate duplicate seriesof port segments.

FIG. 5 is a view similar to FIG. 4 showing a modification.

Referring to the drawings, the flow control valve generally designatedincludes a two-part stationary cylindrical shell 11 having a frontflange 12 and a rear flange 13. An axially extending lip 14 on theflange 12 has a central cylindrical opening 15. A cup element 17 isprovided with a cylindrical side wall 18 and an integral domed end wall19. The cylindrical wall 18 slides within the opening 15. The cup 17 isprovided with an enlarged flange 21 which receives one end of the coilcompression spring 22 mounted within the shell 11.

The other end of the spring 22 engages one of the series of annularshims 23 held by the spring against the rear flange 13.

One or more of the flow control valves 10 may be employed within thesplit housing 26, as shown in FIG. 2. A barrier wall 27 within theinterior of the housing 26 is provided with a plurality of openingswithin circular seats 28 for reception of cooperating shoulders 29provided on the shells 11. Fasteners 30 and washers 31 engage theshoulders 29 to prevent displacement of the shells 11 from the barrierwall 27. Each cup 17 is provided with apertures or ports described indetail below, so that fluid may flow from the inlet pipe 31 into thechamber 32 within the housing and then through the ports in the cup 17,through the interior of the shells 11, into the housing space 33 and outthrough the discharge pipe 34. Pressure in the housing chamber 32 causeseach cup 17 to slide axially into its respective shell 11 against theaction of its spring 22. This general plan of operation is set forth insaid prior U.S. Pat. Nos. 3,131,716 and 3,256,905.

In accordance with the present invention, the ports in the cylindricalwall 18 of the movable cup 17 do not comprise single symmetrical taperedslots which extend axially for the full range of movement (as in priorU.S. Pat. Nos. 3,131,716 and 3,256,905 but instead the cup side wall 18is provided with several axially extending series of circumferentiallystaggered separate port segments 41, 42, 43 and 44. This group of portsegments 41, 42, 43 and 44 constitutes one series. The several seriesmay or may not be duplicates. The cup 17 may have one such series or aplurality of such series depending on the desired flow capacity; sixduplicate series are shown in the drawings.

The shape of the individual port segments and their relative positionare chosen so that the rate of flow of fluid through the port segmentsremains substantially constant for any axial position of the movable cup17 with respect to the circular opening 15 in the stationary shell 11.The pressure in the housing inlet chamber 32 acts on the end wall 19 ofeach movable cup against the action of the spring 22. The parts are inthe position shown in FIG. 1 only when a very low pressure differentialexists between the housing inlet chamber 32 and the discharge chamber33. For greater pressure differentials, the cup 17 slides back throughthe opening 15 into the interior of the shell 11, thereby cutting offsome of the combined area of port segments exposed to pressure in thechamber 32. As the differential pressure increases, the spring isfurther compressed so that less and less combined port area is availableto handle the volume of fluid flow. Thus the port segments 41, 42, 43and 44 in any one series are shaped so that their combined total areaexposed to pressure in the chamber 32 varies in an inverse manner withrespect to the force of the spring for any position of the cup relativeto the stationary member. This inverse manner is not a straight-linefunction; for constant flow, the port area must change in inverseproportion to the square root of the pressure differential. As set forthin U.S. Pat. No. 3,131,716, the mathematical expression of the formula Ak/ {71 or more precisely expressed A Q/kC {'X' where A is the totaleffective area, X is the pressure differential, K is a constant, Q is arelatively constant flow rate, k is a proportionality constant, and C isthe overall discharge coefficient of the flow passages.

It will be noted that the port segments 41, 42, 43 and 44 decrease incircumferential width toward the end wall 19 of the cup 17. Also,adjacent port segments 41 and 42 have end boundaries 41a and 42apositioned in substantially the same transverse plane normal to the cupaxis A--A (FIG. 3). Similarly, adjacent port segments 42 and 43 have endboundaries 42b and 43a which are in substantially the same transverseplane. Also, adjacent port segments 43 and 44 have end boundaries 43band 4411 which are in substantially the same transverse plane. A verynarrow gap or overlap" may be tolerated, but essentially the endboundaries are in the same transverse plane, as stated.

The series of port segments provide interlaced metal sections whichretain more of the cylindrical structure by minimizing or dispersing theinterruption of the circumferential surface of the cylindrical portion18 of the cup. This also provides greater strength in the cylindricalwall 18 and reduces the tendency of internal stresses to distort thecylindrical configuration after the port openings have been cut out. Ithas been found that it eliminates the need for reforming the cylindricalportion 18 after the port segments are cut. Where the cylindricalportions 18 of the cup 17 are to be precision finished, as in acenterless grinder, the segmented port interlaced metal pattern providesa more continuous circumferential surface condition and consequently theground surfaces are more uniformly cylindrical. Furthermore, there is asignificant functional advantage of the segmented ports as compared tocontinuous tapering ports shown in said prior patents, in that foreignmatter which may tend to enter a port segment is confined to the squaredoff limits of that port segment, rather than being wedged into a furthernarrowing section of a single continous port. This means that foreignobjects are much more apt to pass through the segmented ports or to becut off, rather than wedged or trapped therein.

It has been found highly desirable from a manufacturing and fabricationstandpoint to design the port segments so that one axially extendingside is straight and lies in a plane containing the axis A-A of the cup17. Accordingly, it will be observed that the side boundaries 41c, 42c,43c and 44c are each straight and each lies in a plane containing theaxis of the cup. The opposite side boundary of each port segment iscurved to meet the requirements of the formula as expressed above.

The series of round holes 50 provided in the cylindrical surface 18 nearthe end wall 19 may vary in number and size. These bypass holes 50comprise a major part of the total minimum area, the balance being thearea of the clearance between the cup and the opening 15.

Tests have shown that for any given axial position of the cup 17relative to the opening 15, the same flow rate is achieved for the sametotal exposed port area whether a few large ports or many small portsegments are employed. The explanation appears to be that the increasedflow friction due to edge effect of the many port segment openings isoffset by an improvement in equal distribution of pressure differentialacross the full opening of each port segment.

In the modified form of the invention shown in FIG. 5, the long thinport segments 44 for each series of port segments are not employed.Instead, each alternate series is provided with one wider port 45 whichproduces the same flow characteristics as two separate thin ports 44.The thin ports 44 inherently narrow down to a minimum required width,and there is a practical limit to the minimum width that can beprovided. The various series need not be duplicates, and the combinedsegmented ports in a series may supplement more than one series or partthereof. Moreover, any of the port segments, except the largest ones,may be combined in this manner.

By segmenting these ports and combining the area change requirements oftwo or more ports into a single port segment, lower minimum port areachange requirements can be met within the practical minimum port widthlimitations. While, for the above reasons, it is desirable toconsolidate one or more parts to cover the minimum width portrequirements, it is not practical to consolidate ports to cover themaximum width port requirements. This is true because of limitations asto how much of the cylindrical cups circumference should be cut by anindividual port. Therefore, the segmented port concept makes itpractical to consolidate ports to meet minimum width port requirementsand retain individual port segments to cover the maximum port width arearequirements.

Having fully described my invention, it is to be understood that I amnot to be limited to the details herein set forth but that my inventionis of the full scope of the appended claims.

I claim:

1. A flow control valve having, in combination: a stationary memberprovided with an opening, a ported element mounted to slide axiallywithin said opening and having at least one axially extending series oflaterally staggered separate port segments, the port segments in saidseries each continuously decreasing in. lateral width from end to endtoward one end of said element, adjacent port segments in the serieshaving end boundaries in substantially the same transverse plane.

2. The flow control valve of claim 1 in which each port segment isnon-symmetrical and has one straight side boundary defined from end toend by a plane con taining the axis of movement of the ported element.

3. The flow control valve of claim 1 in which each series of separateport segments has a first segment, a second segment and a third segment,the large end of the second segment being identical in shape and widthto the small end of the first segment, and the small end of the secondsegment being identical in shape and width to the large end of the thirdsegment.

4. In a flow control valve having a stationary member provided with anopening, and having a cup mounted to slide axially within said opening,the improvement comprising: a side wall forming a portion of the cup,said side wall having at least one axially extending series of laterallystaggered separate port segments, the port segments in said series eachcontinuously decreasing in lateral width from end to end toward one endof the cup, adjacent port segments in the series having end boundariesin substantially the same transverse plane.

5. The flow control valve of claim 4 in which each port segment isnon-symmetrical and has one straight side boundary defined from end toend by a plane containing the axis of movement of the ported element.

6. The flow control valve of claim 4 in which each series of separateport segments has a first segment, a second segment and a third segment,the large end of the second segment being identical in shape and widthto the small end of the first segment, and the small end of the secondsegment being identical in shape and width to the large end of the thirdsegment.

7. The flow control valve of claim 4 in which a plurality of series ofseparate port segments are provided, at least one of said series havingan additional axially extending port segment of greater lateral widththan the adjacent port segment in that series.

8. The flow control valve of claim 4 in which at least two duplicateseries of separate port segments are provided, one only of said twoseries having an additional axially extending port segment of greaterlateral width than the adjacent port segment in that series.

9. A flow control element for use in a flow control valve, comprising: acup having a side wall and an end wall, said side wall of the cup havingat least one axially extending series of laterally staggered separateport segments, the port segments in said series each continuouslydecreasing in width from end to end toward said end wall of the cup, andthe adjacent port segments in the series having end boundaries insubstantially the same transverse plane normal to the cup axis.

10. The flow control element of claim 9'in which a plurality of seriesof separate port segments are provided, at least one of said serieshaving an additional axially extending port segment of greatercircumferential width than the adjacent port segment in that series.

11. The flow control element of claim 9 in which at least two duplicateseries of separate port segments are provided, one only of said twoseries having an additional axially extending port segment of greatercircumferential width than the adjacent port segment in that series.

12. A flow control element for use in a flow control valve, comprising:a cup having a side wall and an end wall, said side wall of the cuphaving at least one axially extending series of laterally staggeredseparate port segments, the port segments in said series eachcontinuously decreasing in width from end to end toward said end wall ofthe cup, the adjacent port segments in the series having end boundariesin substantially the same transverse plane normal to the cup axis, eachport segment having one side boundary defined by a plane containing thecup axis.

13. A flow control element for use in a flow control valve, comprising:a cup having a cylindrical side wall and an end wall, said side wall ofthe cup having at least one axially extending series ofcircumferentially staggered separate port segments, the port segments insaid series each continuously decreasing in circumferential width fromend to end toward said end wall of the cup, the adjacent port segmentsin the series having end boundaries in substantially the same transverseplane normal to the cup axis.

14. In a flow control valve having a stationary member provided with acircular opening, and having a cup mounted to slide axially within saidopening against the action of a aging, the improvement comprising: acylindrical side wall forming a portion of the cup, said side wallhaving at least one axially extending series of circumferentiallystaggered separate port segments, the port segments in said series eachcontinuously decreasing in circumferential width from end to end towardone end of the cup, adjacent port segments in the series having endboundaries in substantially the same transverse plane normal to the cupaxis, and the port segments in the series being shaped so that theirtotal exposed area on one side of the circular opening varies in aninverse manner with respect to the force of the spring for any positionof the cup relative to the stationary member.

15. A flow control valve having, in combination: a stationary memberprovided with a circular opening, a valve element having a cylindricalwall slidable within said opening, said wall having a plurality ofaxially extending duplicate port segments each continuously decreasingin lateral width from a large end to a small end, the small ends of theduplicate port segments lying in the same transverse plane, said wallhaving at least one additional axially extending port segment decreasingcontinuously in lateral width from a wide end to a narrow end, eachadditional port segment having its wide end lying substantially in saidtransverse plane, but circumferentially staggered with respect to eachof said l elisatqmnsssm m 16. The flow control valve of claim 15 inwhich each of said duplicate port segments is non-symmetrical and hasone straight side boundary defined from end to end by a plane containingthe axis of m vsm totsaid v lvesle 17. A flow control valve having, incombination: a stationary member prtrided with acircular opening, avalve element having a cylindrical wall slidable within said opening,said wall having a plurality of axially extending duplicate portsegments each continuously decreasing in lateral width from a large endto a small end, the small ends of the duplicate port segments lying inthe same transverse plane, said wall having a plurality of additionalaxially extending port segments each decreasing continuously in lateralwidth from a wide end to a narrow end, each additional port segmenthaving its wide end lying substantially in said transverse plane, butcircumferentially staggered with respect to each of said duplicate portsegments, the total combined width of said wide ends of the additionalport segments having the same transverse width as the total combinedwidth of the small ends of said duplicate port segments.

18. The flow control valve of claim 17 in which each of said duplicateport segments is non-symmetrical and has one straight side boundarydefined from end to end by a plane containing the axis of movement ofsaid valve element.

1. A flow control valve having, in combination: a stationary memberprovided with an opening, a ported element mounted to slide axiallywithin said opening and having at least one axially extending series oflaterally staggered separate port segments, the port segments in saidseries each continuously decreasing in lateral width from end to endtoward one end of said element, adjacent port segments in the serieshaving end boundaries in substantially the same transverse plane.
 2. Theflow control valve of claim 1 in which each port segment isnon-symmetrical and has one straight side boundary defined from end toend by a plane containing the axis of movement of the ported element. 3.The flow control valve of claim 1 in which each series of separate portsegments has a first segment, a second segment and a third segment, thelarge end of the second segment being identical in shape and width tothe small end of the first segment, and the small end of the secondsegment being identical in shape and width to the large end of the thirdsegment.
 4. In a flow control valve having a stationary member providedwith an opening, and having a cup mounted to slide axially within saidopening, the improvement comprising: a side wall forming a portion ofthe cup, said side wall having at least one axially extending series oflaterally staggered separate port segments, the port segments in saidseries each continuously decreasing in lateral width from end to endtoward one end of the cup, adjacent port segments in the series havingend boundaries in substantially the same transverse plane.
 5. The flowcontrol valve of claim 4 in which each port segment is non-symmetricaland has one straight side boundary defined from end to end by a planecontaining the axis of movement of the ported element.
 6. The flowcontrol valve of claim 4 in which each series of separate port segmentshas a first segment, a second segment and a third segment, the large endof the second segment being identical in shape and width to the smallend of the first segment, and the small end of the second segment beingidentical in shape and width to the large end of the third segment. 7.The flow control valve of claim 4 in which a plurality of series ofseparate port segments are provided, at least one of said series havingan additional axially extending port segment of greater lateral widththan the adjacent port segment in that series.
 8. The flow control valveof claim 4 in which at least two duplicate series of separate portsegments are provided, one only of said two series having an additionalaxially extending port segment of greater lateral width than theadjacent port segment in that series.
 9. A flow control element for usein a flow control valve, comprising: a cup having a side wall and an endwall, said side wall of the cup having at least one axially extendingseries of laterally staggered separate port segments, the port segmentsin said series each continuously decreasing in width from end to endtoward said end wall of the cup, and the adjacent port segments in theseries having end boundaries in substantially the same transverse planenormal to the cup axis.
 10. The flow control element of claim 9 in whicha plurality of series of separate port segments are provided, at leastone of said series having an additional axially extending port segmentof greater circumferential width than the adjacent port segment in thatseries.
 11. The flow control element of claim 9 in which at least twoduplicate series of separate port segments are provided, one only ofsaid two series having an additional axially extending port segment ofgreater circumferential width than the adjacent port segment in thatseries.
 12. A flow control element for use in a flow control valve,comprising: a cup having a side wall and an end wall, said side wall ofthe cup having at least one axially extending series of laterallystaggered separate port segments, the port segments in said series eachcontinuously decreasing in width from end to end toward said end wall ofthe cup, the adjacent port segments in the series having end boundariesin substantially the same transverse plane normal to the cup axis, eachport segment having one side boundary defined by a plane containing thecup axis.
 13. A flow control element for use in a flow control valve,comprising: a cup having a cylindrical side wall and an end wall, saidside wall of the cup having at least one axially extending series ofcircumferentially staggered separate port segments, the port segments insaid series each continuously decreasing in circumferential width fromend to end toward said end wall of the cup, the adjacent port segmentsin the series having end boundaries in substantially the same transverseplane normal to the cup axis.
 14. In a flow control valve having astationary member provided with a circular opening, and having a cupmounted to slide axially within said opening against the action of aspring, the improvement comprising: a cylindrical side wall forming aportion of the cup, said side wall having at least one axially extendingseries of circumferentially staggered separate port segments, the portsegments in said series each continuously decreasing in circumferentialwidth from end to end toward one end of the cup, adjacent port segmentsin the series having end boundaries in substantially the same transverseplane normal to the cup axis, and the port segments in the series beingshaped so that their total exposed area on one side of the circularopening varies in an inverse manner with respect to the force of thespring for any position of the cup relative to the stationary member.15. A flow control valve having, in combination: a stationary memberprovided with a circular opening, a valve element having a cylindricalwall slidable within said opening, said wall having a plurality ofaxially extending duplicate port segments each continuously decreasingin lateral width from a large end to a small end, the small ends of theduplicate port segments lying in the same transverse plane, said wallhaving at least one additional axially extending port segment decreasingcontinuously in lateral width from a wide end to a narrow end, eachadditional port segment having its wide end lying substantially in saidtransverse plane, but circumferentially staggered with respect to eachof said duplicate port segments.
 16. The flow control valve of claim 15in which each of said duplicate port segmeNts is non-symmetrical and hasone straight side boundary defined from end to end by a plane containingthe axis of movement of said valve element.
 17. A flow control valvehaving, in combination: a stationary member provided with a circularopening, a valve element having a cylindrical wall slidable within saidopening, said wall having a plurality of axially extending duplicateport segments each continuously decreasing in lateral width from a largeend to a small end, the small ends of the duplicate port segments lyingin the same transverse plane, said wall having a plurality of additionalaxially extending port segments each decreasing continuously in lateralwidth from a wide end to a narrow end, each additional port segmenthaving its wide end lying substantially in said transverse plane, butcircumferentially staggered with respect to each of said duplicate portsegments, the total combined width of said wide ends of the additionalport segments having the same transverse width as the total combinedwidth of the small ends of said duplicate port segments.
 18. The flowcontrol valve of claim 17 in which each of said duplicate port segmentsin non-symmetrical and has one straight side boundary defined from endto end by a plane containing the axis of movement of said valve element.